Fix compliance with Jupyter 5.0 spec for idle messages

main/Main.hs

@@ -191,6 +191,10 @@ runKernel kOpts profileSrc = do
           -- Write the reply to the reply channel.
           liftIO $ writeChan (shellReplyChannel interface) reply
 
+      -- Notify the frontend that we're done computing.
+      idleHeader <- liftIO $ dupHeader replyHeader StatusMessage
+      liftIO $ writeChan (iopubChannel interface) $ PublishStatus idleHeader Idle
+
   where
     ignoreCtrlC =
       installHandler keyboardSignal (CatchOnce $ putStrLn "Press Ctrl-C again to quit kernel.")
@@ -290,10 +294,6 @@ replyTo interface req@ExecuteRequest { getCode = code } replyHeader state = do
       publish = publishResult send replyHeader displayed updateNeeded pOut (usePager state)
   updatedState <- evaluate state (T.unpack code) publish widgetMessageHandler
 
-  -- Notify the frontend that we're done computing.
-  idleHeader <- liftIO $ dupHeader replyHeader StatusMessage
-  send $ PublishStatus idleHeader Idle
-
   -- Take pager output if we're using the pager.
   pager <- if usePager state
              then liftIO $ readMVar pOut
@@ -440,8 +440,4 @@ handleComm send kernelState req replyHeader = do
           -- Only sensible thing to do.
           return kernelState
 
-  -- Notify the frontend that the kernel is idle once again
-  idleHeader <- liftIO $ dupHeader replyHeader StatusMessage
-  liftIO . send $ PublishStatus idleHeader Idle
-
   return newState